<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title></title>
  <script src="../G.js"></script>
  <style>
    ul{ list-style-type: none;height: 30px; line-height: 30px; overflow: hidden;}
    ul li{height: 30px; line-height: 30px; }
  </style>
</head>
<body>
<ul>
  <li><a href="www.baidu.com">hello</a></li>
  <li><a>world</a></li>
  <li><a>世界</a></li>
  <li><a>你好</a></li>
</ul>
<script>
  function roll(){
    //$("li")
    return  $("ul")[0].appendChild($("li")[0]);
  }
  setInterval(roll,2000);
</script>
</body>
</html>